Process of and apparatus fob distilling petroleum



Oct' 8, 1929. E. H. LESLIE ET AL 1,730,891

PROCESS OF AND APPARATUS FOR DISTILLING' PETROLEUM Filed March 20, 1923 Patented Get. 8, 1929 Pr t.

EUGENE H. LESLIE AND EDVIIN M. BAKER, 03E ANN ARBOR, MICHIGAN PROCESS OF AND APPARATUS FOR DISTILLING PETROLEUIE Application filed .March 20, 192

This invention relates to'a process of and ap niratus for distilling hydrocarbon solutions or mixtures such as petroleum and the like.

The invention has as an object the separation. of one or a number of different products from hydrocarbon mixtures such as petroleum and analogous solutions or mixtures,

It has also as an object the providing of an api iaratus for effecting this result and also for treating various other liquids which may be treated. in this type of apparatus.

In the preferred embodiment of the invention as illustrated in the accompanying drawings which form part of this specification there is shown the plant for distilling and fractionating petroleum, this plant being composed of a number of apparatus units comprising a fractionator, a vaporizer and a pipe-still. The structure and operation of the fractionator and vaporizer have been given in detail in our corresponding applications Ser. Nos. 626,274: and 626,273 filed March 20, 1023, and reference is made specifically to these cases for further description of the various uses to which these forms of apparatus may be put. In the present embodiment the various units have been arranged to provide a plant for distilling petroleum to separate therefrom volatile fractions such as gasolene, and the apparatus will therefore be described in connection with the production of commercial gasolene.

In the drawings the figure illustrates the above mentioned complete plant for the fractionation of petroleum or hydrocarbon miX- turcs.

For the sake of clearness the description will proceed with respect to the sequence of operations in the treatment of petroleum. Petroleum enters the plant or system through a heat exchanger 1 to a pipe-still 2 in which the oil is heated to a predetermined temperature such, for example, as 400 or 500 F., and r the passage through the pipe-still is of a short duration, preferably from three to five minutes. If desired, a ore-vaporizer 3 may be provided in the piping, the pre-vaporizer having a vapor zone 4, and zones 5 and 6 filled with suitable packing offering a large Serial No. 626,275.

surface and preferably a free-space of over 60%, The oil passing through the pipe-still leaves it through the pipe 7 and enters a main vaporizer 8 Which is suitably provided With a lagging to prevent loss of heat. A baffle plate 9 is mounted beneath the mouth of the pipe in order to distribute the oil over a mass of suitable packing 9 offering a large surface and preferably a freespace of over 60%. As a result of the opportunity afforded by the packing for contact of liquid and vapor, a state of equilibrium is speedily obtained, and the liquid residuum flows off through an exit pipe 10 to the heat exchangers and the volatilized portions of the liquid pass upwardly through a packing zone 10 similar to the zone 9, and which serves to remove liquid droplets entrained in the vapor, and thence pass through the passage 11 to a fractionator 12. A pump 13 continuously pumps the liquid from the pie-vaporizer to the pipe-still and thence into the main vaporizer. A float 1% may be introduced in the bottom of the vaporizer 8, and connected to a balance Valve 15, in order to provide a constant level of oil in the bottom of the vaporizer.

The fractionator 12 is provided 'Wltll a number of sections as shown, these sections having nipples 16 so arranged that liquid collects and is trapped so that it may be Withdrawn through the pipes 17 if desired, yet so arranged that they permit liquids to overflow from one section to another and vapors to ascend through the various sections of the fractionator. Each section as desired may be provided with pipes 17 through which, by suitable valved connections to manifolds 171, 172, liquids may be withdrawn or introduced and also, if desired, With pipes 17* through which vapors may be Withdrawn. There is also provided in each section a mass of suitable packing material, preferably such as to offer a large surface and free-space. At the top of the fractionator a baffle 18 is provided below a vapor outlet pipe 19, leading to a condenser 20 that is designed to function as a reflux condenser and return the condensed liquid through a pipe 21 to the top of a baflie 22 provided over the top section of the fractionator. Any gases not condensed in the condenser pass out through a pipe 28. If desired, the distillate or vapor collected from any section may be passed through a distillate cooler 2% or vapor condenser 2a, which may act either to cool liquids or condense vapors. It is preferable, however, to withdraw the products from the various sections in the form of liquids, as the necessity for providing numerous condensers is thereby avoided and the products can be handled in small pipes rather than in the large pipes required for vapors.

In some instances it will be desirable to provide means for withdrawing a liquid resi due from the bottom of the fractionator, heating it to drive off a predetermined portion of vapors therefrom, and returning the vapors to the bottom of the fractionator in order to supply the said fractionator with additional vapor that will be condesed and thus provide an additional weight of reflux liquid and thus increase the efficiency of operation as more fully described in our said co-peuding application Ser. No. 626,274. This auxiliary heater may take the form of a cylindrical still, or it may preferably be in the form illustrated, which consists of a pipe-still constructed similar to the still 2, in combination with an auxiliary vaporizer 26 constructed substantially as the vaporizer S. The residuum from the fractionator is withdrawn through a pipe 27 and conducted to the still or heater 25, and to the vaporizer 96. The vapors from the vaporizer 26 are returned to the fractionator through a pipe 28, and the residue from the vaporizer 26 is withdrawn from the system through the pipe 28.

In case it is desired to supply steam to the fractionator in order to establish a partial pressure of water vapor therein, the steam pipe 29 is shown connected to the bottom of the fractionator although itis to be understood that steam or wag-er or a petroleum liquid may be injected into other sections or any section thereof, or into the vaporizer 8.

In the operation of the apparatus, as illustrated in the present example, crude petroleum is introduced through the conduit 1 and is heated to a predetermined temperature, say lOO to 500 F, in the coils of the pipe still, wi h the use of the prevaporizer 3, the use of this prevaporizer, however, being not essential in the broader aspects of the invention, although it is dis inctly desirable. The function of this prevaporizer is to drive oil light hydrocarbons and all or part of any water that may be present, and also to eliminate dissolved gases, these constituents being objectionable in further heating the oil because they reduce the rate of heat transferred in the pipes of the pipe still. After these lighter constituents are removed, the heating of the oil is continued as it passes through the remainder of the pipes of the pipe still and the hot oil, superheated with respect to its content of relatively volatile constituents, such as gasoline, kerosene, etc, is delivered to the main vaporizer 8, the pressure on the oil being at the same time released. As the oil flows down through the packing material which, as already pointed out, provides enormous liquid-filming surface in conjunction with very large free vapor space, rapid flash vaporization takes place and a condition of equilibrium between vapor and liquid is speedily obtained. As a result, the desired portion of volatilized liquid, cleanly separated as equilibrium vapor by the action of the vaporizer from that portionof the oil which it is not desired to vaporize, ascends through the upper packing zone 10" where entr ined liquid droplets are removed from the vapor before it passes upwardly through vapor outlet 11 into the base of the fractionator. The vapors pass upwardly through the various sections of the fractionator, where they come into intimate contact with the descending liquid, thus progressively changing in composition until the top of the fractionator is reached. Practically all condensation takes place in the reflux condenser above the fractionator, and the liquids therein condensed are returned to the top section. thereby providing a continuous supply of liquid flowing down the fractionator. The composition of the liquid and vapor in each particular section is difi'erent from that in the adjacent sections, and the liquid and vapor in each section will be approximately in a state of equilibrium by reason of contact of vapor and liquid on the surfaces of packing material employed. The obstruction to the flow of the vapors will be comparatively small. Petroleum distillates of various compositions may be withdrawn from the various sections of the fractionator as desired, the amount of liquid or vapor withdrawn from any particular section having a direct effect on the functioning of the entire system. The sections from which liquid should be withdrawn will be determined by the composition of the products it is desired to make, and with respect to the effect of the withdrawal of liquid from a particular section on the functioning of the other sections of the fractionator.

Although the invention has been set forth with respect to the treatment of petroleum it will be apparent that other liquids may be similarly treated in so far as they are susceptible of similar treatment in an apparatus of this kind.

As many apparently widely different embodiments of our invention may be made without departing from the spirit thereof, it is to be understood that we do not limit ourselves to any particular embodiment except as defined in the following claims.

o claim:

1. Apparatus for distilling liquids which comprises, in combination, means for heating the liquid, a flash vaporizer connected thereto and arranged to receive heated liquid there from, a fractionator into which said vaporizer delivers vapor, and a reflux condenser connected to the upper part of said fractionator and arranged to condense vapor leaving the fractionator and to reflux liquid condensate thereto, said apparatus being further characterized by the fact that said flash vaporizer has a vapor outlet and a liquid outlet and means whereby liquid from said heating means is introduced into the vaporizer between said outlets, said vaporizer being pro vided with a packing zone between said liquid outlet and the point at which liquid is intr0- duced into the vaporizer from said heating means.

2. Apparatus for distilling liquids which comprises, in combination, means for heating the liquid, a flash vaporizer connected thereto and arranged to receive heated liquid therefrom, a fractionator into which said vaporizer delivers vapor, and a reflux condenser connected to the upper part of said fractionator and arranged to condense vapor leaving the fractionator and to reflux liquid condensate thereto, said apparatus being further characterized by the fact that said flash vaporizer has a vapor outlet and a liquid out let and means whereby liquid from said heating means is introduced into the vaporizer between said outlets, said vaporizer being provided with packing zones located between the point at which liquid is introduced into the vaporizer from said heating means and said vapor outlet and said liquid outlet, respectively.

3. Apparatus for distilling liquids which comprises, in combination, a pipe still, a prevaporizer arranged to receive partially heated liquid from said pipe still and to return the liquid thereto for further heating after removal of volatile constituents therefrom, a vaporizer having a vapor outlet and a liquid outlet, a conduit through which heated liquid is delivered from the pipe still into said vaporizer at a point intermediate said outlets, packing zones arranged, respectively, be tween said point of introduction and said vapor outlet, and between said point of introduction and said liquid outlet, a fractionator connected to said vaporizer and arranged to receive vapor therefrom, and a reflux condenser arranged to reflux liquid condensate to the upper part of said tractionator.

4. Apparatus for distilling liquids comprising, in combination, means for heating the liquid, a flash vaporizer; a tractionator comprising a number of sections placed one above the other, with means for introducing vapor at the bottom, reflux means for returning condensed vapor at the top, means for permitting countercurrent contacting of liquids and vapors and for trapping and collecting liquid, and means for permitting the withdrawal of liquid products from sections as desired, and means for permitting the withdrawal of vapor products as desired.

5. Apparatus for distilling liquids comprising, in combination, means for heating the liquid, a flash vaporizer; a iractionator comprising a number of sections placed'one above the other, with means for introducing vapor at the bottom, reflux means for returning condensed vapor at the top, means for the introduction or withdrawal of liquid into or from any of a number of sections, means for permitting counterc-urrent contacting of liquids and vapors, means for trapping and collecting liquid, and means for permitting the withdrawal of vapor products as desired.

6. Apparatus for distilling liquids comprising, in combination, means for heating the liquid, a flash vaporizer; a fractionator comprising a number of sections placed one above the other, with means for introducing vapor at the bottom, means for returning condensed vapor at the top, means for permitting countercurrent contacting of liquids and vapors, means for trapping and collecting liquid, means for permitting the withdrawal of liquid products from sections as desired; a second vaporizer, connections whereby liquid of reflux origin may be supplied thereto from the lower part of the fractionator and vapor may be returned therefrom to the lower part of the fractionator, and a reflux condenser arranged to reflux liquid condensate to the upper part of the fractionator.

7. Apparatus for distilling liquids comprising, in combination, means for heating the liquid, a flash vaporizer; a fracti-onator comprising a number of sections placed one above the other, with means for introducing vapor at the bottom, means torreturning condensed vapor at the top, means for permitting countercurrent contacting of liquids and vapors; means for the withdrawal of vapor products from sections of the fractionator as desired; a second vaporizer, connections whereby liquid of reflux origin may be supplied thereto from the lower part of the fractionator and vapor may be returned therefrom to the .lower part of the fractionator, and a reflux condenser arranged to reflux liquid condensate to the upper part of the fractionator.

8. Apparatus for distilling liquids comprising, in combination, means for heating the liquid, a flash vaporizer; a fractionator comprising a number of sections placed one above the other, with means for introducing vapor at the bottom, means for returning condensed vapor at the top, means for permitting countercurrent contacting of liquids and vapors, means for trapping and collecting liquid, means for permitting the withdrawal of liquid products from sections as desired, and means for permitting the withdrawal of vapor products as desired; a second vaporizer, connections whereby liquid of reflux origin may be supplied thereto from the lower part of the tractionator and vapor may be returned therefrom to the lower part of the fractionator, and a reflux condenser arranged to reflux liquid condensate to the upper part of the fractionator.

9. Apparatus for distilling liquids comprising, in combination, means for heating the liquid; a flash vaporizer having a vapor outlet and aliquid exit, m ans for introducing liquid thereto, and an upper pachng zone between said inlet and outlet and-a lower packing zone between saiu inlet and exit; a traetionator comprising a number of sections placed one above the other, with means for introducing vapor at the bottom, reflux means for returning condensed vapor at the top, means for permitting countercurrent contact-- ing of liquids and vapors and for trapping and collecting liquid, means for permitting the withdrawal oi liquid products from sections as desired, and means for permitting the withdrawal of vapor products as desired.

10. The process of distilling petroleum comprising heating it to predetermined temperature, introducing the heated petroleum into a vaporizer, removing unvaporized residue from the vaporizer, conducting the vapor from the vaporizer to a fractionator comprising series of superimposed sections,

bringing the ascending vapor into intimate contact with descending liquid reflux in the fractionator, conducting vapor from the top of the i'ractionator to a reflux condenser, returning condensed vapor as liquid reflux to the top of the fractionator, trapping and collecting liquids in the sections of the fractionator, and withdrawing liquid products from sections of the fractionator as desired, and withdrawing vapor products from sections oi the fractionator as desired.

11. The process of distilling petroleum comprising heating it to a predetermined temperature of srq erheat in a pipe-still, introducing the heated petroleum into a vaporizer in which the heated petroleum is dis tributed over a very large surface and a mixed vapor is flashed oil, removing unvaporized residue from the vaporizer,,conducting the vapor ii'rom the vaporizer to a fractionator comprising a series of superimposed sections, bringing the ascending vapor into intimate contact with descending liquid reflux in the tractionator, conducting vapor from the top of the tractionator to a reflux condenser, returning condensed vapor as liquid reflux to the top of the tractionator, trapping and collecting liquids in he sections of the fractionator, and withdrawing liquid products from sections of the fractionator as desired, and withdrawing vapor products "from sections of the fractionator as desired.

resid ue from the vaporizer, causing the vapor to pass through a zone of packing material, conducting the vapor from the vaporizer to fractionator comprising a series of superimposed sections, bringing the ascending vapor into intimate contact with descending liquid reflux in the tractionator, conducting vapor from the top of the fractionator to a reflux condenser, returning condensed vapor to the top of the l ractionator, trapping and collecting liquids in the sections of the fractionator, and withdrawing liquid products from se *tions of the fractionator as desired, and withdrawing vapor products from sections of the fractionator as desired.

13. The process of distilling petroleum compri a heating it to a predetermined tempuature, introducing the heated petrolcuni into a vaporizer, removing unvaporized res due from the vaporizer, conducting the vapor from the vaporizer to a tractionator comprising a series at superimposed sections, brr mg the ascending vapor into intimate cont W with descending liquid reflux in the tractionator, conducting vapor from the top of the fractionator to a reflux condenser, returning condensed vapor as liquid reflux to the top of the fractionator, introducing petroleum liquid other than the reflux condensate into any section of the :lractionator, trapping and collecting liquids in the sections of the fractionator, withdrawing liquid products from sections of the fractionator as desired, and withdrawing vapor products from sections of the iractionator as desired.

1.4.. The process of distilling petroleum comprising heating it to a predetermined temperature, introducing the heated petrd leum into a vaporizer, removing unvaporized residue from the vaporizer, conducting the va ior from the vaporizer to a tractiouator comprising a series oi; superimposed sections, introducing steam into any section of the fracti nator, bringing the ascending vapor into intimate contact with descending liquid reflux in the fractionator, conducting vapor from the top of the tractionator to a reflux condenser, returning condensed vapor as liquid reflux to the top of the fractionator, trapping and collecting liquids in the sections oi. the tractionator, withdrawing liquid products from sections of the tractionator desired, and withdrawing vapor products om sections of the tractionator as desired. In testimony that we claim the foregoing, we have hereunto set our hands this 8th day of March, 1923.

EUGENE H. LESLIE. EDWIN M. BAKER. 

